图像探测器像素位置偏差标定方法设计

Design of image detector pixel geometric offset calibration method

为了减少星敏感器等空间姿态测量仪器的测量误差,提升星点定心精度,通过研究图像探测器像素位置偏差对定心精度的影响,提出了一种基于相移干涉原理的像素位置偏差标定方法。基于像素响应不均匀性,构建具有像素位置偏差的探测器仿真模型并进行星点定心计算,仿真结果证明了像素位置偏差会导致定心结果产生系统误差。探测器像素标定结果表明,在添加均方根值为0.03 pixel的像素位置偏差以及5%幅值比的高斯白噪声条件下,该探测器像素标定方法的标定精度优于3×10-4 pixel(1σ),研究结果为探测器像素位置偏差标定技术提供一种可行的方案,对于提升星敏感器等姿态测量仪器的测量精度具有重要意义。

In order to reduce the measurement errors of space attitude measuring instruments such as the star trackers,and improve the centroid accuracy of star point,a calibration method based on the phase-shifting interferometry principle was proposed,by studying the influence of the image detector′s pixels geometric offset on the centroid accuracy of star point.The simulation model of image detector based on the properties of pixel response nonuniformity with pixels geometric offset was built,and the star centroid calculation was carried out in simulation.The simulation results proved that the pixels geometric offset of the image detector would produce parts of systematic errors to the centroid accuracy of star point.The image-detector pixel calibration results showed that under the condition of adding pixels geometric offset with the RMS value of 0.03 pixels and the 5%Gaussian white noise in the amplitude ratio,the calibration accuracy of the image detector pixel calibration method was better than 3×10-4 pixel(1σ).The research results turned to be a feasible scheme for the calibration technology of the pixels geometric offset of image detector,and had great significance to improve the measuring accuracy of attitude measuring instruments such as the star trackers.